Targ S.M. 1988 K2 option 74

The flat mechanism consists of rods 1-4 and the slider B connected to each other and to the fixed supports O₁ and O₂ by hinges. Rod lengths ℓ₁=0.4m; ℓ₂ = 1.2m; ℓ₃ = 1.4m; ℓ₄ = 0.8m. The position of the mechanism is determined by the angles α; β; γ; φ; θ. Point D in all figures and point K in the middle of the corresponding rod. Determine the values indicated in the table. Find also the acceleration of point A of the rod 1, if at the given moment the angular acceleration ε₁ = 10c⁻².